You could do it using unpack, but it leaves it up to you to group back into pairs. 
$ perl -E'say for unpack "(x4 A X5 A4x/A)*", $ARGV[0]' \
   '0004$ADAM0002*330004%19770004$BOB 0002*430004%1967'
$
ADAM
*
33
%
1977
$
BOB
*
43
%
1967

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In reply to Re: Splitting file into separate files based on record lengths and identifiers by ikegami
in thread Splitting file into separate files based on record lengths and identifiers by monty77

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